Relay mechanism



Aug. 4, 1931. A. N. VAN Nos TRAN!) I 12,817,468

RELAY" uncmuusu Filed Sept. 4. 1929 2 Sheets-Sheet I mmvrox.

f U a -M' ATTORNEYS.

Aug. 4, 1931. A. N. VAN NOSTRAND RELAY MECHANISM 2 Sheets-Sheet 2 Filed Sept. 4. 1929 INVENTOR,

ATTORNEYS.

Patented Aug. 4, 1931 UNITED STATES PATENT OFFICE ARLEIGH N. VAN NOSTRAND, OF FLUSHING, NEW YORK, ASSIGNOR TO TELAUTOGRAPH CORPORATION, OF NEW YORK, N. Y A-CORPORATION 0F VIRGINIA RELAY MECHANISM Application filed September 4, 1929. Serial No. 390,269.

This invention relates to improvements in relay mechanisms in telautograph systems.

I The general object of the invention is to provide a sensitive and reliable relay which will respond to relatively weak alternating or pulsating currents and which will have a certain range of adjustment as well as permanence of operating characteristics once the initial adjustments have been effected.

While relays of this general type have been used heretofore in connection with telautograph penlifting apparatus, the construction of such prior relays has not been entirely satisfactory from the standpoint of reliability and durability. The present invention avoids these disadvantages, and comprises certain features, details of construction and combination of parts which will be described in connection with the accompanying drawings and more fully pointed out in the appended claims.

In the drawings, Figure 1 is a plan view, partly broken away, of a relay now considered as the best embodiment of this invention.

Figure 2 is a side elevation of the same relay, partly in section to show the interior arrangement. Figure 3 is an enlarged view, partly in section of a portion of the mechanism.

Figure 4 is a circuit diagram of as much of a telautograph system as is necessary to clearly'show the application of this relay.

Referring to Figures 1 and 2 of the drawings, 1 is the frame or bracket portion of the apparatus, made preferably of brass or other non-magnetic metal and having two arms, 2 and 3, extending horizontally at right angles from it.

The lower arm 2 of the frame serves as a support for a cup shaped member 7 of nonmagnetic material such as brass, which houses an electro-magnetic assembly consisting of a pair of electro-magnets 8, 8 secured to the ends of yoke pieces 10, lO respectively by means of screws 9, 9 threaded into their cores. The other ends of the yokes, which are of magnetic material such as iron, are secured by means of bolts 11, 11 to opposite poles of a permanent horse shoe type magnet 12. Screws 13 passing through the arm 2 and cup 7 and threaded into the yokes 10, 10 serve to hold the assembly in place. The upper rim of the cup 7 is flanged to form a groove or seat for the reception of a diaphragm 14 of magnetic material such as soft iron. At the center of the diaphragm, and secured thereto in any suitable manner, as for example, by riveting, is a hook shaped member 15, of nickel silver or similar metal, the purpose of which will later be described. The diaphragm with its hook is held in position relative to the cup by means of spring retaining ring 16 which is arranged to be snapped into position and held in firm contact with the upper surface of the diaphragms periphery by the slightly inturned rim of the cup. The proportioning of the parts of the apparatus is such that when the diaphragm is seated, the space between it and the upper end of the cores of the electromagnets is relatively small. An important feature of the invention consists in providing the diaphragm 14 with notches or serrations, leaving relatively long tongues between the notches, for the purpose of rendering the diaphragm very flexible and resilient, thereby obtaining greater amplitude of vibration under conditions of operation, as will later appear. The windings of the electro-magnets 8,8 are connected in series and the two leads immediately therefrom are attached, as by soldering, to heavier lead wires 15,15 which are secured to the inside of the cup by means of a clamping device 17, in any suitable way, as for example, by bolt and nut 18. The lead wires pass out through holes in the bottom of the cup to form convenient terminals. 7 s

It will be understood that the magnetic circuit for the polarizing horse shoe magnet 12, and for the electro-magnets 8, 8 is common, extending from one pole of magnet 12, through yoke piece 10, core of electro-magnet 8, across small air gap to and through diaphragm 14, across a second small air gap to core of electro-magnet 8 yoke piece 10, to opposite pole of permanent magnet 12. The action of the polarizing flux is to exert an attractive pull on the diaphragm toward the cores of the electro-magnet and hold the diaphragm in a state of tension. The action of the flux generated by the electro-magnets when an alternating or pulsating current is passed through their windings, is to vibrate the diaphragm at a frequency corresponding to the current frequency.

The upper and shorter arm portion 3 of bracket 1 is slotted to receive the cylindrical member 4: which is drilled eccentrically for the passage of bolt 5, which also passes laterally through the extending journal pieces 3, 3 of the arm 3 and is secured in position by nut 6. In practice the cylinder at is rigidly pinned to the bolt 5, so that it may be readily rotated by turning the bolt with a wrench and then locked in the desired position by tightening the nut (S. In effect the eccentrically mounted cylinder forms an adjustable cam, the purpose of which will presently appear.

Attached to the upper surface of the arm 3, by means of screw 20 and flat washer 21, is a plate spring member of suitable material such as phosphor bronze, extending from its point of attachment across the upper surface of the cylindrical cam l. and engaging at its outer end the under surface of hook 15 attached to the diaphragm. The outer end of the spring is circularly formed to embrace and hold firmly a microphonic contact device shown enlarged and partly in section in Figure 3. This portion ot' the apparatus consists of a tube of insulating material, such as glass or bakelite, into each end of which is fitted a specially formed plug 26, 26 of metal, such as brass. These plugs are identical in construction and only one has been shown in section. *ach consists of a cylindrical portion within the bakelite tube, a shoulder portion 27, and a terminal portion 28, to which leads may be attached. The plugs are held firmly relative to the tube by cup shaped members 29, of soft metal, such as copper. Each of these cup shaped parts has a hole for the easy passage of the terminal portion 28 of the respective plug. The parts are spun into grooves in tube 25, as the drawing clearly shows, to form a rigid assembly. The cylindrical portion of each plug is drilled out to form a centrally located recess 30, at the rim of which is fitted an annular contact 31 of suitable metal, such as platinum, the inside diameter of the contact being substantially less than the inside diamet r of the recess 30. \Vithin the tube 25 is a contacting member consisting of a cylindrical body 32 of metal, such as brass, having two contact pins of tungsten or platinum, one protruding at each end. The diameter of the pins 33 is somewhat less than the inside diameter of the ring contacts 31, and, as assembled, each pin enters through the respective contact. By this means the cylinder 32 is supported clear of the tube 25.

The cylinder 32 is of such a length as to allow it some slight end play between the ring contacts 31 of the plugs 26, 26.

Plug 26 is connected by a flexible lead to washer terminal 3%. Plug 26 is connected to spring 22 and frame of the apparatus by means of a wire 35 soldered to the terminal portion of the plug and to the spring. Thus, washer 34 forms one terminal of the circuit including the loose contact mechanism and screw 36 threaded through the frame 1 forms the other terminal. This screw also serves to hold the complete device to the panel of a telautograph apparatus, not shown.

It will be understood from the construction as described, that when an alternating or pulsating current passed through the windings 8, 8 the diaphragm 14 will be agitated and this agitation will be transmitted through hook 15 and the circularly formed section of spring 22 to the tube 25 and the parts therein. The result is to vibrate the cylinder 32 and its contacts 33 relative to the plugs 26, 26 and their contacts 31. J long as the diaphragm continues to vibrate, the contact pins 33 will continue to bounce against their co-acting ring shaped contacts 31. At each of the two points where the circuit is thus interrupted the time that either pin contact is in electrical connection with its respective ring contact is relatively very small. The fact that two such points of interruption are in series and that current can only flow when both points of interruption are electrically closed at the same instant makes the mean values of current through a circuit, including this vibrating contact device, practically negligible. hen, however, the pulsating current ceases to flow through windings 8, 8, diaphragm 14 quickly comes to rest and ceases to agitate the contact mechanism, whereupon contacts 33 come to rest firmly upon contacts 31 and an electrical circuit having relatively low resistance completed through them.

Referring to Figures 1 and 2, it will be seen that by rotating cam 4t by means of screw :3, the plate spring 22 may be given various values of tension, thus exerting any desired upward pressure and diaphragm 14;, which will be flexed to increase the air gap between it and the cores of the electro-magnets by any desired amount. In this wa the sensitivity and responsiveness of the relay may be varied to the required extent.

The operation of the relay will now be described in connection with Figure 4: which shows in an elementary manner the right and left writing line circuits, and other cir- 9 cuits closely related thereto, employed when one telautograph transmitting instrument T is connected to two receiving instruments B, Rp. One receiving instrument R is located adjacent to the transmitter to serve as 11 against hook 15 pilot or guide for the operator as he writes. while the other, R, is located. at a distance. The right and left line circuits of one receiver are each connected in multiple with the respective line circuit of the other receiver. The line circuits are adjusted to uniform resistance and each instrument receives the same value of current from the transmitter. As the receivers are identical, only the circuits of that designated as B have been shown, and the circuits will be described in connection with that receiver.

At the transmitting instrument are the usual pair of rheostats T T connected to a source of direct current D whose negative pole is grounded. From these rheostats the writin currents are shunted into the right and le t writing lines by means of contact rollers and levers T, T in the well known manner. The writing currents divide at junctions J and J 2 and flow to the pilot receiver over conductors LR and LLp, and over conductors LR and LL to the distant receiver R, passing through the respective right and left line relay windings RR- and BL and bucket windings BR and BL and ,returning via ground to the generator at the transmitter. Shunted across the right and left lines at the receiver is a circuit extending from J 3 to J 4 and including a condenser C and the windings 8, 8 of a relay constructed as herein before described. The loose contact mechanism of this relay is indicated at 32 and is included in a series circuit with the winding of the penlifting electro-magnet Pm and with a suitable source of direct current, as for example a generator D.

A source of pulsating curent is provided at the transmitter, controlled by the underplaten contact which operates with the pressure of the transmitter stylus on the writing platen. While any of a number of methods of generating a pulsating current could be used, a preferred method is shown, consisting of a circuit traceable from the positive pole of generator D at junction J 5 through resistance R short circuiting buzzer, or interrupter B resistance R to negative pole of generator at junction One terminal of the interrupter B is connected to the right writing line through condenser C while the other terminal of the interrupter is connected to the left writing line through condenser C The underplaten contact U normally short circuits the interrupter B, rendering it inoperative, but when pressure is applied to the transmitter platen by the stylus in writing, this contact opens and allows current to pass through the interrupter winding. The armature of the interrupter is drawn toward the core until contacts B close and short circuit the winding, whereupon the armature returns and opens the contacts B and the vibrating cycle begins again. It will be understood that the interrupter B continues to vibrate when the stylus is in contact with the platen and ceases to vibrate when the stylus is raised, as between the written words or figures. At the moment of breaking there exists at the buzzer terminals a relatively great difference of potential which is impressed on right and left lines respectively through condensers C and C This otential difi'erence drops to zero when the buzzer contacts close. It will be seen therefore that a pulsating current is impressed on the writing lines as long as the interrupter B continues to vibrate. Choke coils are provided at K and K to prevent the pulsating current passing back to the transmitter rheostats, and to direct the major portion over the writing lines.

to the local receiver R and distant receiver B. At the receiver R the pulsating current passes through condenser C and windings 8, 8 rather than through the highly inductive metallic circuit containing the relay and bucket windings ER, BB, BL and RL, and operates to vibrate the loose contact mechanism 32 and open'the circuit of the penlifter magnets Pm, allowing the receiver pen to touch the paper in unison with the operation of the transmitter stylus.

What is claimed is:

1. A relay comprising an electromagnet, a magnetic diaphragm adapted to be vibrated by the electromagnet, said diaphragm having notches providing peripheral radial tongues, a loose contact circuit controlling device, and an operative connection between the diaphragm and loose contact device whereby diaphragm vibrations are imparted to said device.

2. A relay comprising an electromagnet, a magnetic member adapted to be vibrated by the electromagnet, a loose contact circuit controlling device adapted to be vibrated by the magnetic member in unison therewith, and an adjustable spring mounting for the loose contact device.

3. A relay comprising an electromagnet, a magnetic diaphragm adapted to be vibrated by the electromagnet, a hook member attached to the diaphragm, a loose contact circuit controlling device positioned to be engaged and vibrated by the hook, a leaf spring supporting said contact device, and tension adjusting means for the spring;

In testimony whereof, I have hereunto set my hand AR'LEIGH N. VAN NOSTRAND. 

